Electric regulator



April 9 1940. s. MINNECI ELECTRIC REGULATOR Filed Jab. 5. 1938 LINE DROP CUMPENSA T01? R Wm R WM L0 Inventor: Salvatore Mi .neci, b3 76 44171 3 His btorney- Patented Apr 9, 1940 UNITED STATES PATENT OFFICE ELECTRIC REGULATOR Salvatore Minneci, Pittsfleld, Mass, assignor to General Electric Company, a corporation of New York This invention relates to electric regulators and it has for an object the production of an automatic electric regulator which is adapted for use in electric circuits in which the power flow reverses.

The invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

Referring now to the single figure of the accompanying drawing, wherein is illustrated diagrammatically an embodiment of the invention, the main regulated apparatus is shown by way of example as a single phase alternating current power circuit I. For purposes of illustration and explanation, the voltage of circuit I will be taken as the main regulated quantity. This voltage is regulated by a regulator 2. This regulator may be of any well-known type, such, for example, as

a large load-ratio-control power transformer or a feeder voltage regulator of either the step or induction types and it is illustrated by way of example as a step voltage regulator consisting of an auto transformer having a common winding 3, a tapped series winding 4 and an auxiliary supply winding 5. Taps are changed on the series winding by means of a tap changing switch 4' operated by a reversible motor 0.

The starting, stopping and reversing of motor 0 in response to voltage is controlled by means of a primary relay 1 of any suitable type, such, for example, as a contact-making voltmeter of the type described in Champlin Patent 2,039,632. Compensation for the voltage drop in the line or power circuit between the regulator and the load center or center of distribution is made by line drop compensators 0 and 9 of any suitable and well-known type, such, for example, as the type described in Gehrkens Patent 1,100,723.

Automatic power directional control of (a) the connections between the primary relay and the power circuit; (b) the connections of the line drop compensating means, and (c) the connece tions between the primary relay and the motor are all controlled by a master reverse current or power directional relay Hi. This relay may be of any well-known construction and is shown by way of example as being of the induction disk type having a current winding I I and a potential winding It.

The current winding II is energized by means of a current transformer 13 which transformer, for the sake of economyand simplicity, may also supply current for the line drop compensator 0. The potential winding II is energized by the auxiliary winding 5. Relay [0 is provided with a set of contacts which in the illustrated form of the invention, may be considered as the equivalent of a single-pole double-throw switch. The arrangement is such that, when the power flow through the circuit Ii is in one direction, one set of contacts is closed and the other set is opened and when the power flow reverses, the previously closed contacts open and the previously opened contacts close.

In order to protect the circuit against a trembling or chattering engagement of the master relay contacts, a pair of auxiliary relays l4 and ii are provided. These relays are controlled respectively by the two sets of contacts of the master relay. Relay I4 is provided with a set of seal in contacts it which are connected across the contacts of the master relay which control the energization of the relay [4 so that this relay seals itself in as soon as it is actuated. Relay i5 has a set-of contacts ll in the energizing circuit of the relay l4 and the arrangement is such that whenever relay I5 is energized, it breaks the energizing circuit for the relay I4 and thereby causes this relay to drop out. In this manner, relay It will immediately pick up and seal itself in whenever it is actuated and thereafter the opening of the master relay contacts or their trembling engagement will have no effect on relay it until there is a definite power reversal which will cause the master relay to close its second set of contacts, thereby energizing relay l5 and causing relay H to drop out.

A set of contacts I0,'controlled by auxiliary relay I4, control the connection of the primary relay I to one side or the other of the regulator. In the position shown, the primary relay is connected to respond to the voltage on the right hand side of the regulator, as viewed in the drawing, by means of a potential transformer I9.

When the auxiliary relay I4 is actuated, this energizing circuit of the primary relay is broken and the primary relay is connected to respond to the voltage on the left hand side of the regulator by connecting it to the auxiliary winding 5.

A second set of contacts 20, controlled by the auxiliary relay I, control the selective connection of the line drop compensators 8 and 9 in the energizing circuit of the primary relay 1. With the contacts 20 in the position shown, the line drop compensator 9, which is energized by a current transformer 2|, is connected in circuit with the primary relay, while in the other position of these contacts, the line drop compensator 8 will be connected in circuit with the primary relay.

A third set of contacts 22 are controlled by the auxiliary relay l5. reversing switch between the direction of operation controlling terminals of the motor 6 and the raise (R) and the lower (L) contacts of the primary relay.

The motor 5 is energized in any suitable manner, such, for example, as by connecting it across the potential transformer l9 through conductors 23 and 24, as illustrated.

The operation of the illustrated embodiment of the invention is as follows: Assume that power circuit l is a part of a live electrical transmission or distribution system and that power is flowing through the circuit from left to right as viewed in the drawing. Assume further that the voltage on the right hand, or output side of the regulator under the assumed conditions of power flow, is normal. Under these conditions, the parts will all be in their illustrated positions. It now the voltage should change for any reason, the primary relay will respond and will close either its raise or its lower contacts depending upon whether the voltage is too low or too high. This will complete a circuit for the motor 6 through the contacts 22 and the motor will turn in such a direction as to cause the tap changing switch 4' to insert more of the series winding 4 in the circuit if the voltage is too low, or less of the series winding in the circuit in case the voltage is too high provided that the transformer is a boosting transformer. Of course, if it is a bucking transformer, the action of the tap switch will be just the opposite in order to secure the desired regulating eliect. As soon as the voltage returns to normal, the primary relay will open its contacts and the regulator will stop.

Assume now that the power flow through circuit l reverses and flows from right to left, as viewed in the drawing. This reversal of power flow may be caused in a number of different ways. For example, if circuit l is a tie line between two power systems, reversal of power flow will be a common and deliberately produced occurrence in order to achieve the full benefits oi the interconnection. Again, if circuit l is part of a loop circuit the tripping of a circuit breaker on one side or the other of the regulator will often automatically cause a reversal of power flow.

As soon as the power flow does reverse, the master relay ID will respond and will complete the energizing circuit for the auxiliary relay M which immediately seals itself in, as previously described. The actuation of the auxiliary relay l4 causes the primary relay to be connected to the auxiliary winding 5 and to be disconnected from the potential transformer l9. This, therefore, insures that the primary relay will respond to the regulated or output voltage of the regulator which voltage will now appear to the left hand side of the regulator instead of on the right hand side of the regulator.

The operation of the contacts 20 in response to the actuation of the relay l4 will disconnect the line drop compensator 9 from the primary relay and will connect the line drop compensator 8 in the energizing circuit of the primary relay. These compensators may or may not have similar settings. If they do have similar settings, it is, of course, unnecessary to have two line drop compensators and either one may be dispensed These contacts constitute 2).-

correct for the reversal of current with respect to the circuit voltage. In other words, as present day alternating current power systems are of the so-called constant voltage type, reverse power really means reverse current with respect to the circuit voltage, so that as the primary relay responds to a voltage which does not change direction with change in power flow, it will usually be necessary to interchange the compensator connections so as to correct for the reversed voltages produced by the compensator upon reversal of the power flow. Also, in many systems a reversal of power flow is accompanied by a shift in the load center or center of distribution, so that different amounts of line drop compensation will be necessary with different directions of power flow. This is automatically taken care of by means of the two line drop compensators, each of which may be set to produce the desired amount of line drop compensation from the regulator to the different points at which constant voltage isto be maintained for the different directions of power flow. However, it will, of course, be obvious to those skilled in the art that two line drop compensators are not essential and that contacts 20 could also be adapted to change the setting of one compensator by changing its internal connections.

The contacts 22 reverse the connections between the primary relay contacts and the motor, so as automatically to correct for the fact that the regulator must be operated in the reverse di rection upon reversal of power flow. Thus, with power flowing from right to left, and assuming the transformer to have been a boosting transformer, with respect to left-to-right power flow, the motor must be operated in such a direction as to cause the tap switch 4 to cut out sections of the series winding in order to raise the voltage and to add sections of the series winding in order to lower the voltage. In other words, the transformer is now a bucking transformer.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the invention and, therefore, it is aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent oi the United States, is:

1. In a regulator system, in combination, apparatus through which power may flow in opposite directions, a regulator for controlling the value of a variable quantity which is a factor of said power flow, a primary device responsive to said quantity for controlling said regulator, and means responsive to a reversal of power flow in said apparatus for reversing the controlling effect of said primary device on said regulator.

2. In a regulator system, in combination, an electric circuit in which the direction of power flow reverses, a voltage regulator connected in said circuit, a primary relay connected to be responsive to the voltage of said circuit for controlling said regulator, and a power directional relay for reversing the controlling effect of said primary relay on said regulator in response to a reversal of power flow through said circuit.

3. In a regulator system, apparatus through which power may flow in opposite directions, a regulator of a variable quantity which is a factor of said power flow connected in said apparatus,

a primary device responsive to said quantity for 7 controlling said regulator, and means responsive to the direction of power flow through said apparatus for changing the side 01' said regulator to which said. primary device is connected to respond to said quantity.

4. In a regulator system, in combination, an electric power circuit in which the direction of power flow reverses, a voltage regulator connected in said circuit, a primary voltage sensitive device for controlling said regulator, and a power directional relay for selectively connecting said primary voltage sensitive device to respond to the voltage on different sides of said regulator in accordance with the direction of power flow through said circuit.

5. In combination, an alternating current power circuit in which the direction of power ilow reverses, a transformer having a common winding connected across said circuit and a. series winding connected in said circuit on one side of said common winding, a potential transformer connected across said circuit on said side of said common winding, an auxiliary low voltage winding on said transformer inductively related to said common winding, means for changing the voltage ratio between said common ,and series windings, a primary voltage sensitive relay for controlling the direction of operation of said ratio changing means in a manner to maintain constant circuit voltage, and a power directional relay for selectively causing the connection of said primary relay across said auxiliary winding if the power flow through said circuit is in one direction and across said potential transformer if the power flow through said circuit is in the reverse direction.

6. In a voltage regulating system, an electric power circuit in which the direction 01 power flow reverses, a voltage regulator therein, a primary relay for controlling said regulator in accordance with the voltage of said circuit, line drop compensating means for correcting the response of said primary relay for the voltage drop in said circuit, and a power directional relay for changing the effect oi said line drop compensating means on said primary relay in response to a reversal 01 power flow through said circuit.

7. In a voltage regulating system, an electric power circuit in which the directional power flow reverses, a voltage regulator therein, a primary relay for controlling said regulator in accordance with the voltage of said circuit, line drop compensating means for correcting the-response of said primary relay for the voltage drop in said circuit, and means including a power directional relay for reversing the effect of said line drop compensating means on said primary relay in response to a reversal of power flow through said circuit.

8. In a voltage regulating system, an electric power circuit in which the direction of power flow reverses, a voltage regulator therein, a primary relay for controlling said reg; :tor in accordance with the voltage of said circuit, line drop compensating means for correcting the response of said primary relay for the voltage drop in said circuit, and means including a power directional relay for both' reversing and changing the magnitude of the eflect of said line drop com-.

pensating means on said primary relay in response to a reversal of powe fl t u said I circuit.

9. In combination, an alternating current power circuit in which the direction of power flow reverses, a voltage regulator connected therein,

a primary relay for controlling said regulator in response to the voltage of said circuit, a pair of line drop compensators connected to be responsive to the current in said circuit, said compensators being set to provide difierent amounts of compensation, and a power directional relay for causing the connection of one of said line drop compensators in circuit with said primary relay in accordance with one direction of power flow through said circuit and causing the connection of the other of said line drop compensators in circuit with said primary relay in response to a reversal of said direction of power flow.

10. In a regulator system, an electric circuit in which the direction of power flow reverses, a voltage regulator connected therein, a primary relay for controlling the direction of operation of said regulator in response to the voltage of said circuit, a power directional relay responsive to the direction of power flow in said circuit, means controlled by said power directional relay i'or reversing the control of said regulator by said primary relay in response to a reversal of power flow through said circuit, and means controlled by said power directional relay for selectively connecting said primary relay across said circuit on diiIerent sides of said regulator in accordance with the direction of power flow through said circuit.

11. In a regulator system, in combination, an electric circuit in which the power flow reverses, a voltage regulator therefor connected in said circuit, a primary relay for controlling said regulator in accordance with the voltage of said circuit, line drop compensating means for said primary relay, a power directional relay responsive to the direction of power flow in said circuit, means controlled by said power directional relay for reversing the control of said regulator by said primary relay in response to a reversal of power flow through said circuit, and means controlled by said power directional relay for changing the eii'ect of said line drop compensating means on said primary relay in response to a reversal of power flow through said circuit.

12. In a regulator system, an electric circuit in which the direction of power flow reverses, a voltage regulator for said circuit connected therein, a primary relay for controlling said regulator in accordance with the voltage of said circuit, line drop compensating means for said primary relay, a power directional relay responsive to the direction of power flow in said circuit, means controlled by said power directional relay for connecting said primary relay to respond to the voltage of said circuit on the output side of said regulator regardless of the direction of power flow through said circuit, and means controlled by said power directional relay for changing the eii'ect of said line drop compensating means on said primary relay in response to a reversal of power flow through said circuit.

13. In a regulator system, an electric circuit in which the direction of power flow reverses, a voltage regulator for said circuit connected therein, a primary relay for controlling said regulator in accordance with the voltage of said circuit, line drop compensating means for said primary relay, a power directional relay responsive to the direction of power flow in said circuit, means controlled by said power directional relay for reversing the controlling eiIect of said primary relay on said regulator in response to a reversal of power flow through said circuit, means through said circuit, and means controlled by said power directional relay for changing the effect of said line drop compensating means on said primary relay in response to a reversalof power flow through said circuit.

14.1n an electrical distribution system. an alternating current feeder circuit in which the power fiow reverses, a step voltage regulator connected in said circuit, a primary voltage sensitive relay for controlling the direction of operation of said regulator in response to the voltage of said circuit, a pair of line drop compensators connected to be energized by the current in said circuit and adapted to be connected selectively in circuit with said primary relay, 9. power directional relay responsive to the direction of power flow in said circuit, and an auxiliary relay controlled by said power directional relay, said auxiliary relay being provided with means for selectively controlling (a) the direction of regulator response to said primary relay, (b) the side of said regulator to which said primary relay is connected and (c) whichever line drop compensator is connected in circuit with said primary relay. 1 SALVATORE MINNECI.

DISCLAIMER 2,196,87 1./S'alvat0re M innecz', Pittsfield, Mass. ELECTRIC REGULATOR. Patent dated April 9, 1940. Disclaimer filed July 19, 1941,by the assignee, Gemral Electrio Uompany.

Hereby enters this disclaimer to'claims 1, 2, 3, 4, 6, 7, 10, 11, 12, and 13 of said Letters Patent.

[Official Gazette August 12, 1.941.]

DISCLAIMER 2,196,871.Salvatore Minneci, Pittsfield, Mass. ELECTRIC REGULATOR. Patent dated April 9, 1940. Disclaimer filed July 19, 1941, by the assignee, General Electm'o Company. Hereby enters this disclaimer to'claims 1, 2, 3, 4, 6, 7, 10, 11, 12, and 13 of said Letters Patent.

- [Oyficz'al Gazette August 12, 1941.] 

